The human T-lymphotropic viruses (HTLV) are members of a family of exogenous human retroviruses. The most widely known human retrovirus is HIV-I human immunodeficiency virus, the AIDS virus. Two HTLV viruses, HTLV-I and HTLV-II, are widely spread; with HTLV-I playing the larger role in illnesses and being especially prevalent in tropical and subtropical environments throughout the world. The HTLV-I virus is associated with adult T-cell leukemia (ATL), tropical spastic paraparesis (TSP).sup.1 and HTLV-I associated myelopathy (HAM in Japan).sup.2. It is characteristic of HTLV-I infection that a period of up to 20 years may pass from the time of infection up to the appearance of symptoms.sup.3. The HTLV-II virus has been less studied. It has been isolated from some individuals with hairy cell leukemias.sup.4. While it was not recognized until 1982, hairy cell leukemia is being diagnosed with increased frequency. It affects mainly older adult males with fatigue, malaise, infection (often with atypical organisms), abdominal discomfort, pancyteopenia, splenomegaly and lymphadenopathy.sup.5. Current research has shown that HTLV-II is endemic in isolated Indian tribes in Central America .sup.11 and frequently occurs in intravenous drug users.sup.12.
Infection with HTLV-I or II can be detected by the presence of antibodies to each of the viruses. Detection techniques include enzyme-linked immunosorbent assays for the detection of antibodies to the virus or to viral components, immunofluorescence and Western blotting. The viruses themselves have been detected by reverse transcriptase activity of culture supernatants, immunofluorescent antibodies directed against viral antigens and sandwich enzyme immunoassays. These techniques are based on studies on the proteins encoded by the HTLV-I and II genomes. The major protein groups are: "tax," whose gene product is a transactivation protein with a molecular weight of 40,000 daltons.sup.6 ; "env" (envelope), which has three gene protein products--gp 61, gp 43 and gp 21.sup.6 ; "pol," a reverse transcriptase protein, p96.sup.6 ; and "gag," which encodes for the major core proteins p53, p24, p19 and p15.sup.6. The p33 antigen found on HTLV-I has been described as a possible fusion protein of the "gag" and "tax" gene products.sup.10.
Monoclonal antibodies to the HTLV-I virus have been described in the following U.S. Pat. No. 4,722,888 to Broder et al. describes murine monoclonal antibodies to core antigens p19 and p24; U.S Pat. No. 4,886,743 to Hood et al. describes the use of monoclonal antibodies to amino acid sequences within T-cell receptors and particularly within the variable region of the beta chain of the T-cell receptor as markers for disease diagnosis; No. 4,833,071 to Wang et al. describes the detection of HTLV-I antibodies by the use of chemically synthesized peptides having amino acid sequences corresponding to segments of the envelope protein p21; U.S. Pat. No. 4,804,746 to M. Yoshida et al. describes an antibody to a human leukemia virus-related peptide; U.S. Pat. No. 4,792,524 to Miyoshi describes an ATLA cell strain having 44 chromosomes and being useful to produce a ATLA antiserum; U.S. Pat. No. 4,645,738 to Knowles et al. describes two antibodies to leukemia associated antigens in T-cell acute lymphoblastic leukemia, but do not react with the T-cell lymphoma cell line HUT-102; U.S. Pat. No. 4,588,681 to Sawoda et al. describes a process for producing ATLA antigen and a kit for assaying ATLA antibodies, which process uses the known cell strains MT-1, -2, -3 and -4, and especially MT-2; U.S. Pat. No. 4,572,800 to Shimizu et al. describes HTLV related peptides and antibodies to such peptides, particularly an antibody to peptide having an N-terminal peptide chain of p24, which is known as one of the antigenic proteins of ATLA, and is useful as a hapten for p24; and U.S. Pat. No. 4,525,300 to Yoshida et al. describes an antibody of HTLV related peptides and the synthesis of the peptides. In each of the above, an antibody was identified which bound to an antigen of HTLV-I or to a peptide model of some part of HTLV-I; but no single antibody was identified which recognized both HTLV-I and HTLV-II, and which was directed to core antigens.
Monoclonal antibodies to HTLV-I core antigens have also been described in the prior art. Aoki et al. describes an antibody which recognizes the HTLV-I p19 antigen.sup.7 ; Cogniaux et al. describe a number of antibodies to p19 or p24 or both.sup.8 ; and Palker et al. describes murine monoclonal antibodies to p24.sup.9. Celluar Products, Inc., Buffalo, N.Y., has developed an assay for detecting antigens of HTLV-I which uses rabbit polyclonal antiserum to HTLV antigen coated on plastic microtiter plates to capture antigen, and a monoclonal antibody to HTLV-I p19 to detect the captured antigen. A drawback to the Cellular Products assay is that the monoclonal antibody utilized recognizes only the p19 core antigen.sup.13. The p19 core antigen is present in HTLV-I, but is not present in HTLV-II Current research has shown that HTLV-II is an etiologic agent in humans. It would be highly desirable, therefore, to provide a monoclonal antibody which can detect a core antigen common to both HTLV-I and HTLV-II. This invention provides a specific monoclonal antibody and an enzyme linked immunosorbent assay utilizing said monoclonal antibody for detecting HTLV-I and HTLV-II p24 and p53 antigens in biological samples or in a tissue culture media. Also, the invention includes such an immunoassay to the simian T-cell lymphotropic virus type I (STLV-I) p53 and p24 core antigens.